1. Field of the Invention
The present disclosure is related to automatic injection and retraction devices. More particularly, the present disclosure is related to automatic injection and retraction devices for use with pre-filled syringe cartridges.
2. Description of Related Art
Manually activated pre-filled syringe cartridges are commercially available from a variety of manufacturers. One such example is the HYPAK® syringe, manufactured by Becton Dickinson & Company. Pre-filled syringe cartridges are used in the administration of drug solutions, drug suspensions, antidotes, dietary supplements, and any other liquid medicament (hereinafter collectively referred to as “liquid medicament”) by parenteral injection.
As such, pre-filled syringe cartridges include a medicine compartment, a hypodermic needle permanently affixed to and in fluid communication with the medicine compartment, and a piston slidably received in the medicine compartment. Often times, the pre-filled syringe cartridges include a plunger removably secured to the piston for causing the piston to force the liquid medicament from the needle. Pre-filled syringes are typically prepared by pharmaceutical companies or sterile filling contractors in a sterile filling suite in which the liquid medicament and the syringe are brought together in a sterile manufacturing environment wherein all components and drug solutions are isolated from microbial contamination. Pre-filled syringe cartridges also include a needle sheath removably positioned over the needle, wherein the sheath is removed just prior to use. The needle sheath serves to protect the needle from physical damage and maintains the fluid path in a sterile condition until it is removed prior to use.
Blood borne diseases such as AIDS, Hepatitis C, and others, are increasing within the general population. The onset of these diseases has increased the desire to prevent inadvertent needle sticks during the use of injection apparatus, including pre-filled syringe cartridges. In order to mitigate inadvertent needle sticks, many pre-filled syringe cartridges include a safety guard that covers the needle once withdrawn from the patient.
In contrast to manually activated pre-filled syringe cartridges, automatic injection devices, commonly known as “auto-injectors”, are also available. Such auto-injectors, once triggered by the user, use an automatic mechanism to insert a hypodermic needle into the recipient's flesh at the injection site and force the liquid medicament out of a medicine compartment, through the hypodermic needle, and into the recipient. In addition to automatic needle insertion and dose delivery, some auto-injectors also incorporate retraction mechanisms to automatically retract the needle after use. Auto-injectors have proven particularly useful in allowing the medically untrained user to administer a parenteral injection. Auto-injectors help to guise the injection apparatus, which benefits patients exhibiting psychological paranoia (i.e., “needle phobic” individuals and young children). Patients with limited manual dexterity or other physical constraints that may prevent the use of conventional syringes (or pre-filled syringe cartridges) can attain self-reliance in injection therapy through the use of auto-injector technology.
Some auto-injectors have been designed to accept commercially available, manually activated pre-filled syringe cartridges. Unfortunately, such auto-injectors have proven difficult to load with the pre-filled syringe cartridges, have proven ineffective at maintaining the auto-injector in a cocked position, have proven ineffective at maintaining the sterility of the needle, and/or have been too difficult to activate. In order to maintain the sterility of the needle, some prior art auto-injectors are configured to drive the needle through the needle sheath during use, which has been found to increase patient discomfort and increase a risk of “coring” the elastomeric needle sheath.
Accordingly, there is a need for automatic injection and retraction devices that overcome, alleviate, and/or mitigate one or more of the aforementioned and other deleterious effects of the prior art.